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ehci-hub: improved over-current recovery

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According to the USB Specification Revision 2.0 chapter 11.12.5
a hub experiencing an over-current condition must place all
affected ports in the powered-off state. It seems that some root
hubs need port power to be cycled by software in order to get back
to normal functionality after an over-current condition ... like
the EHCI implementation on an MPC8343E.

Signed-off-by: Christian Engelmayer <christian.engelmayer@frequentis.com>
Signed-off-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Christian Engelmayer 2007-05-30 11:04:48 -07:00 committed by Greg Kroah-Hartman
parent 648dcfc805
commit 756aa6b3d5
1 changed files with 16 additions and 1 deletions
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17
drivers/usb/host/ehci-hub.c
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@ -647,9 +647,24 @@ static int ehci_hub_control (
status |= 1 << USB_PORT_FEAT_C_CONNECTION;
if (temp & PORT_PEC)
status |= 1 << USB_PORT_FEAT_C_ENABLE;
if ((temp & PORT_OCC) && !ignore_oc)
if ((temp & PORT_OCC) && !ignore_oc){
status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
/*
* Hubs should disable port power on over-current.
* However, not all EHCI implementations do this
* automatically, even if they _do_ support per-port
* power switching; they're allowed to just limit the
* current. khubd will turn the power back on.
*/
if (HCS_PPC (ehci->hcs_params)){
ehci_writel(ehci,
temp & ~(PORT_RWC_BITS | PORT_POWER),
status_reg);
}
}
/* whoever resumes must GetPortStatus to complete it!! */
if (temp & PORT_RESUME) {